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Understanding Root Rot: Symptoms, Causes, and Control

Root rot is a common problem that many plant parents face. It can seriously damage and hurt your loved houseplants, often because they get too frequent watering. Yet, overwatering itself is not the cause of root rot. The excess moisture in the soil encourages harmful fungi growth that attacks the roots.

Seeing your plant start to lose its health but can't find any pests around? Then it could be that your plant is suffering from root rot. Fortunately, if you are on time, it is possible to save your plant. Read all about root rot here!

What is root rot?

Root rot is a plant disease often caused by fungal or bacterial pathogens that attack the roots. Too much moisture creates a perfect environment where these pathogens can thrive and start to damage roots.

The most common fungi causing root rot are Pythium and Fusarium genera species. These pathogens destroy and decompose the root tissues.

It is common to associate root rot with fungal or bacterial infections, but root decay can actually happen without these pathogens. Usually, the problem is caused by overwatering or poor drainage, which results in a lack of oxygen in the soil, and the roots will stop functioning normally. While both lack of oxygen and pathogens can independently cause root rot, it's often a combination of these two.

What does root rot look like?

Root rot typically appears as a wilting, yellowing, or browning of the leaves, while the roots below may become soft, mushy and brown. However, root rot is often difficult to detect until the damage has already been done. It’s because the first symptoms are often under the soil. Foliage symptoms appear after some root damage has already occurred. Here are some signs to look for:

  • Yellowing leaves
  • Brown and crispy leaves
  • Drooping leaves
  • Leaves falling off the plant
  • The plant stem is soft and mushy near the soil surface
  • Soil is extremely moist
  • Soil has a musty and rotten smell

Expert tip! Signs of root rot look a lot like signs of underwatering. If a plant's roots are damaged, it can't drink up the water anymore. So, even if the plant gets lots of water, it can still be thirsty and underwatered. Therefore, it is important to always feel the soil before watering your houseplant again.

In addition, root rot is very easy to recognise by soft, brown roots. If you suspect root rot in your houseplant, remove it carefully from its pot and examine the roots. The root system of a healthy plant is firm and white in colour. If the soil is too soggy, fungi can easily spread. The result? The healthy parts of the root become brown and mushy. In this way, your plant cannot absorb important nutrients, and the lack of these is clearly visible in the plant's leaves.

root rot

How does root rot damage my plants?

Unfortunately, a mistake that many plant lovers make is that they water their plants too much. Plants need water for strength, to grow, to transport nutrition and, when it is warm, to cool down by evaporation. So watering is super important because, without it, a plant will die. However, if you regularly overwater your plants, the soil in the pot will always stay a bit moist or even wet. Most plants don't like this and therefore become more susceptible to fungi that attack the roots.

If a plant is given more water than it can take in, the excess water collects at the bottom of the pot. If the water has nowhere to go, it will find a way to go on its own. In most cases, all the excess water will be absorbed by the plant's roots. Once too much water is absorbed by the roots, root rot can occur. The roots start to rot, become brittle and break down. Eventually, the plant no longer has functioning and healthy roots, and it can no longer absorb water and nutritions nor oxygen. Without these essentials, your plant simply can't survive, and its health starts to decline.

Expert tip! The amount of water your plant needs depends on the plant itself and the environment in which it will be placed. Take this into account and look up the water requirements of your plant.

yellow leaf ficus

How can I prevent root rot?

The good news is that root rot is super easy to prevent! It is simply a matter of the water requirements of the plant. How often and how much water your plant needs depends on the plant and the place where you put it.

6 expert tips on how to prevent root rot

  1. Invest some time and look up what your specific plant watering needs. All plants are a bit different and can have different requirements. Some love more moist soil, while others thrive more in drier soil.
  2. Check the soil every few days to feel its moisture. Just stick your finger into the soil and feel whether the soil is moist or dry, or use a water meter.
  3. Keep track of the days you watered. This way you can avoid making a mistake and accidentally water too much or too little.
  4. Make sure the pot you choose is not too big for your plant. The roots might not be able to withstand the extra water and space in a larger pot.
  5. Choose the right soil for your houseplant. The right potting soil can make all the difference! Go for a well-draining potting soil, ideally one that's not too heavy or holds too much water.
  6. Choose a pot with proper drainage holes. The holes allow excess water to escape and minimise the risk of root rot. Also, keep an eye on the saucers under the houseplants. You should empty them regularly to prevent your plants from getting wet feet!

Don't forget that less is often more. Always check the soil before you water it again, and if you’re not sure if it's the right time to water, dry soil is better than overly wet soil!

How can I control root rot?

Does your plant have root rot? Then you have to stay strong and consistent to save your little plant. Follow four simple steps, and then give your plant a little rest. It needs to recover from the rescue action!

Step 1. Loosening the plant

Take your plant out of its pot and carefully remove as much soil as possible around the roots. You can shake the root ball a little to make the soil come loose or help it loosen with your hands. The roots are fragile and delicate, so be careful! It is no problem if you do not get rid of all the soil as long as you can see the roots.

Expert tip! You can throw away the soil in which your plant stood. It’s overly wet and full of fungus. Soon your plant will have delicious, fresh soil!

Step 2. Cutting the roots

Check carefully to see if the roots have been damaged. You can tell by the colour and strength. Healthy roots are white and firm, while rotten roots will be a bit mushy and brown. Carefully remove all the unhealthy roots. To do this, use a clean and sharp knife or pruning shears so you don't transfer fungus and other bacteria to the healthy roots.

Step 3. Prune the plant

This step sounds a little exciting, but it makes super sense! Because you have probably cut away quite a few roots, the ratio between the plant's foliage and the number of roots is not quite right anymore. This helps to reduce the stress on the plant while it's recovering and growing new roots.

So, after you have removed all the unhealthy roots, you can cut back about 1/2 of the foliage. If you didnt cut a lot of roots away, you can prune it less. Again use a sharp and clean knife and do this carefully.

Step 4. Choose the Right Soil

After pruning, we need to put the plant back in fresh potting soil and give the plant some time to recover. Just remember to choose the proper soil for your green friend. Generally, well-draining potting soil with some perlite is a good choice. Although some plants may benefit from specific types of soil, so make sure to choose one that fits your plant's needs.

We believe in you, you can do this!

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Hi, I'm Emma, your guide!

Hi, I’m Emma, your guide!